Licea atricapilla Nannenga-Bremekamp & Yamamoto (1983: 208)

Bortnikov, Fedor M., Gmoshinskiy, Vladimir I. & Novozhilov, Yuri K., 2022, Species of Licea Schrad. (Myxomycetes) in Kedrovaya Pad State Nature Biosphere Reserve (Far East, Russia), including two new species, Phytotaxa 541 (1), pp. 21-48 : 23-26

* Licea atricapilla Nannenga-Bremekamp & Yamamoto (1983: 208) . Fig. 2 .

Description:—Sporocarps scattered, stalked or rarely sessile, subglobose, usually iridescent excepting a mostly dark apical disk of refuse matter, 105–210 µm in total height, 105–145 µm in diameter. Peridium membranous, outer surface shining, covered on the top by a blackish (65) or rarely lighter cap of refuse matter. Inner peridium surface minutely warted. Dehiscence irregular or nearly circumscissile. Stalk black (267), usually ranges from 1/3 to 1/2 of the total height, but sometimes very short or almost absent. Spores almost black in mass, pale to dark olivaceous-brown (94 to 96) by transmitted light, spore wall with a thinner pale area, (11.1–) 11.5–13.0 (–13.6) µm in diameter, smooth.

Material examined:— LOC 2 (MYX 11289, MYX 11300), LOC 11 (MYX 10203), LOC 17 (MYX 10170, MYX 11314) .

Habitat:—bark of living trees ( Chosenia arbutifolia ), pH: 6.57–6.94 (n = 5).

Distribution:— Japan ( Nannenga-Bremekamp & Yamamoto 1983; Yamamoto 1998), Far East of Russia (approximately 1000 km northwest of the type location in Japan).

Notes:—Our specimens are fully consistent with the original description ( Nannenga-Bremekamp & Yamamoto 1983), although they have slightly smaller sporocarps (105–210 µm in total height vs. 260 µm).

Licea metallica D. Wrigley, T.W. Ko Ko, W.C. Rosing & S.L. Stephenson , described from northern Laos (Wrigley de Basanta et al. 2017) and L. iridescens H.W. Keller & V.M. Marshall , described from the USA ( Keller & Marshall 2019), are similar to L. atricapilla ( Table 1 ). Licea metallica , according to the original description, differs from L. atricapilla by subsessile sporocarps, light apical disc, and irregular dehiscence. However, our Licea atricapilla specimens, along with typical sporocarps on short stalks ( Fig. 2 , A, B, D, and E), have several subsessile sporocarps ( Fig. 2 C and F ), and some specimens have not black but lighter-colored apical disc ( Fig. 2 A ). The sessile form of L. atricapilla also occurs among Japanese specimens (Yamamoto, 1998, p. 136). The dehiscence type in our specimens is unclear, but appears not to be distinctly ring-shaped.

The original description of Licea iridescens does not provide any features distinguishing this species from Licea atricapilla . However, analyzing the description and illustrations, it appears that this species has both sporocarps on short stalks and sessile forms ( Keller & Marshall, 2019, Figs. 4 F and 6 A ). Additionally, the apical disk can be either almost black or lighter-colored, orange-brown (l.c., Fig., 3 F, 4 C, 6 C). Crystal inclusions in the peridium occur both in L. iridescens (l.c., Fig. 4 A ) and in L. atricapilla ( Fig. 2 A ).

The microhabitats of L. atricapilla , L. metallica , and L. iridescens are also similar. Our L. atricapilla specimens were obtained in a moist chamber on the bark of Chosenia arbutifolia with pH 6.57–6.94 (mean = 6,79). L. metallica was found on the bark of unidentified trees with pH 5.0–6.5 (mean = 5.9) (Wrigley de Basanta et al. 2017). In the original descriptions of L. atricapilla and L. iridescens , no data are given on pH of the bark of Cinnamomum camphora and Ulmus americana , respectively; however, according to other studies from the adjacent geographical regions, pH of Cinnamomum camphora is 5.2–7.9 (mean = 6.6) ( Takahashi 2014) and pH of Ulmus americana about 7.0 ( Parker & Keller 2003 as cited by Kilgore et al. 2008). Therefore, all three species apparently prefer the bark of deciduous trees with pH ~ 6–7.

Other features such as characteristics of the outer and inner peridia, size, color, and ornamentation of the spores, height and diameter of the sporocarps, also do not differ significantly between these three species ( Table 1 ). All characteristics vary within a common range. However, we consider L. metallica and L. iridescens as separate morphological species, until a comparison of marker gene sequences and morphological features of our and/or type specimens of L. atricapilla from Japan with the type specimens of L. metallica and L. iridescens are made.

Figures

FIGURE 2. Licea atricapilla (MYX10170: a, e, k; MYX11289: b; MYX11300: d; MYX: 11314: c, f–j). a–d: Sporocarps. e, f: Sporocarps under scanning electron microscope (SEM). g: Inner peridium under SEM. h: Spores by transmitted light (TL). i: Inner peridium under SEM. j, k: Spores under SEM. Scale bars: a–d = 100 µm, e–f = 50 µm, g–k = 5 µm.

FIGURE 4. Licea biforis (MYX10115: a, b; specimen recorded only by photo: c). a–b: Sporocarps. c: Spores by TL. Scale bars: a, b = 100 µm, c = 20 µm.

FIGURE 6. Licea craterioides (MYX10060). a, b: Sporocarps. c: Spores by TL. d: Peridium under SEM. e: Peridium and spores under SEM. Scale bars: a, b = 100 µm, c = 20 µm, d, e = 10 µm.